Seat map for a European flight. Most seats are greyed out (about 50% of them), some have a cross on them. The legend says that the ones with a cross are „occupied“, the grey ones are „not available“. I have seen this many times now.

There isn‘t a pattern either: it‘s not that the seat next to occupied seats is simply greyed out (some Corona measure to give people an individual seat). It‘s sometimes entire rows. On the other hand, seats next to occupied seats are free. It can‘t be for trimming either, the patterns are too random, and one wouldn‘t need to block so many seats for a proper trim.

So what is behind that?